The definitive story-in all its fascinating detail-of the search for life's beginnings. "A highly readable survey of the historical prelude to the study of the origins of life, as well as selected areas of current research, including the search for extraterrestrial life." -Nature Where did we come from? Did life arise on earth or on some other planet? What did the earliest primitive organisms look like? Untangling a century of contentious debate, the authors explore current theories of the source of life-from Martian meteors to hydrothermal vents-and then present their own elegant scenario: Life arose not in the subterranean depths, as many believe, but on Earth's tumultuous surface, where a primitive form of natural selection spawned the first genetic material, perhaps in the form of a proto-virus. Knowing exactly how life began on Earth will not only teach us more about ourselves, it will bring us closer to finding life elsewhere.